Background: The group of unstable hemoglobins are associated with congenital non-spherocytic hemolytic anemia due to instability of the hemoglobin molecule. They often lead to formation of the characteristic inclusion bodies or Heinz bodies.
Aim: To identity the cause of mild anemia, reticulocytosis, and hepatosplenomegly in a case of non-spherocytic hemolytic anemia.
Materials and methods: A 34-year-old female patient originating from Maharashtra, western India presented with mild anemia and jaundice which had persisted since childhood. Investigations included a complete blood count, screening for red cell membrane protein defects, Hb analysis by high-performance liquid chromatography (HPLC) and cellulose acetate electrophoresis (pH 8.9), heat instability test and DNA sequencing.
Results: Hemoglobin analysis by HPLC showed an abnormal peak in the Hb C window (9.8%) with a retention time of 4.90 minutes. Cellulose acetate electrophoresis (pH 8.9) showed a slow moving band (6.15%) between Hb A2 and Hb S. The heat instability test was positive. DNA analysis of α globin genes showed absence of both deletional and non- deletional α thalassemia. DNA sequencing of the β globin gene revealed heterozygosity for a mutation at codon 98 [GTG → ATG, Val → Met], which gives rise to Hb-Koln.
Conclusion: Hb Koln is the commonest unstable Hb variant reported from many populations in the world. However, this is the first report of this unstable Hb variant from India.
Keywords: Hb Koln; India; Non-spherocytic hemolytic anemia; Unstable Hb variant.